Carpenter&#39;s square.



F. W. ROYAL. CARPENTEES SQUARE.

APPLICATION FILED APILZZ, 1910.

975,079. Patented Nov. 8, 1910.

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F. W. ROYAL. GARPBNTERS SQUARE.

APPLICATION FILED APE. 22,1910. I 975,079, Patented Nov. 8,1910.

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FORESTER W. ROYAL, OF BALLSTON, OREGON.

GARPENTERS SQUARE.

Specification of Letters Patent.

Application filed April 22, 1910. Serial No. 556,941.

T 0 all whom it may concern:

Be it known that I, Fonnsrnn WV. RoYAL,-a citizen of the United States,residing at Ballston, in the county of Polk, State of Oregon, haveinvented certain new and useful Improvements in Carpenters Squares; andI do hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same.

This invention squares.

The object of the invention resides in the construction of a squaredesigned for use in quickly and accurately obtaining the lengths andcuts of hip, valley, common and jack rafters without committing tomemory a vast array of figures or resorting to the usual mathematicalsteps to reach the results desired.

With these objects in view the invention consists in the details ofconstruction to be hereinafter referred to and particularly pointed outin the claims.

In describlng the invention in detail reference will be had to theaccompanying drawings wherein like characters of refer.- ence denotecorresponding parts in the several views, and in which:

Figure 1 is a plan View of a square constructed in accordance with theinvention; Fig. 2, a side view of the square showing an edge of theblade and the end of the tongue which constitutes a continuation of saidedge; Fig. 3, a view showing the method of applying the square indetermining the length of a hip or valley rafter; Fig. 4, a view showingthe method of applying the square in determining the length of a commonor a jack rafter; Fig. 5, a view showing the method of utilizing thesquare in determining the roof plane angle of a ack rafter and thevertical angle of both a common and a jack rafter; and, Fig. 6, a viewshowing the method of utilizing the square in determining the verticaland roof plane angles of either a hip or valley rafter.

Referring to the drawings, the square is shown as comprising a tongue Band a blade A disposed in the usual relation. The tongue B isconstructed with its cross section having the shape of an isoscelesright triangle forming corresponding side faces 10 and 11, and a base12. The blade A is atrelates to carpenters tached to the tongue B so asto be in the same plane with the base of said tongue. The length of theblade A is represented as twelve inches and has its inner side scaled ininches as at 13. Likewise the lower edge of the face of the tongue B issealed in inches and fractions of an inch as at 14, said scale beginningat the point of intersection of the lower edge of the side 10 with theinner edge of the blade A and increasing toward the outer end of thetongue B, it being understood that said tongue may be any desiredlength, being shown in this instance as fourteen inches. The base 12 ofthe tongue B has a width of 4.97 inches, thus making the combined lengthof the outer side of the blade A and the width of the tongue B 16.97inches. This combined length of the blade A and the width of the tongueB is divided into twelve equal parts as at 15 (Figs. 1 and 2), each ofsaid divisions thus bearing the same relation to one inch as 16.97 bearsto 1 foot. The lower edge of the side 11 of the tongue B is also sealedin inches and fractions thereof as at 16, said scale extending from endto end of the tongue and increasing from the inner to the outer end.

In measuring rafters it is customary to take 12 inches or one foot asthe basis, therefore in determining the length of a rafter the square isusually applied as many times to the material as the horizontal distancefrom the lower end of the rafter to a point located in a perpendiculardropped from the point where the elevated end of the rafter rests. Forexample :a common rafter on a building four feet wide, with a rise ofsix inches per foot would be 26.83 inches long, or twice the distancecovered by a straight line drawn from six inches on the lower edge ofthe side 10 of the tongue B to the outer end of the inner side of theblade A.

In Fig. 4 of the drawing is illustrated the method of determining thelength of a common or jack rafter to be cut from material M, for use ina building six feet wide, with a roof having a rise of six inches forevery foot of level distance coveredby the rafter to be supplied. DDindicates the working line of the material M and upon a selected pointin this line the outer end of the inner side of the blade A of thesquare is placed, said point constituting the lower Patented Nov. 8,1910. I

end of the rafter. The tongue portion of the square is then moved untilthe six inch scale on the lower edge of the side ofthe tongue B alsorests upon the line D-D. The distance between the outer end of the innerside of the blade A and the six inch scale on the lower edge of the side10 of the tongue B is then set out upon the line D-D and measuredsuccessively thereon three times, the combined distances laid out on theline DD being the length of the common or the jack rafter desired. Theapplication of'the square ust described may be also utilized indetermining the cut or rather the line of cut at the top of a commonrafter for it will be perfectly obvious that a line traced along thelower edge of the side 10 across the material M will give the properangle of cut for disposing the upper end of said common rafter againstthe ridge board. However, as a jack rafter is disposed at its upper endagainst a hip or valley rafter the roof plane angle of said jack rafteror in other words, the angle at which it meets a hip or valley raftermust be determined in a different manner from that just described withrespect to the common rafter and will be presently referred to. Incomputing the length of hip and valley rafters under the, conditionsjust recited the method of utilizing the square differs from thatemployed in the case of common and jack rafters and is illustrated inFig. 3, wherein M represents the material from which the hip or valleyrafter is to be cut and D D the working line thereof. The outer end ofthe outer side of the blade A is placed upon a selected point in saidline, said point constituting the lower end of the rafter and the tongueB moved until the six-inch scale on the lower edge of the side 11coincides with the line D D The distance from the outer end of the outerside of the blade A to the six-inch scale on the side 11 of the tongue Bis then laid off successively three times on the line D D the combinedlength of these distances being the length of the desired hip or valleyrafter. It may be here mentioned that the length of hip and valleyrafters of any redetermined rise for each diagonal foot of evel distancecovered from the angle or corner of a building is the length of thehypotenuse of a right triangle formed by the height of suchpredetermined rise and the hypotenuse of a right angle triangle whosealtitude and base are each twelve inches in length, hence the combinedlength of the outer side of the blade A and the base of the end of thetongue Bis made 16.97 inches, the base of the tongue B being 4.97inches. By embodying these dimensions inthe square 1n the relationdescribed and scaling the combined outer side of the blade A and thebase of the tongue B into the same number of equal parts as the innerside of the blade A, the value of the square in drafting common, jack,hip and valley rafters is maintained.

In order to ascertain the vertical and roof plane angle of the jackrafter having a rise of eight inches per foot and a known length thesquare isv applied as shown in Fig. 5. In this figure the square restsagainst the face of the material M which will constitute the side of therafter with the outer end of the inner side of the blade A coincidingwith the working line D* 5 of said material and the eight inch scale ofthe side 10 also coinciding with the line D*D A straight edge Z or othersuitable instrument is'then placed so as to lie continuously upon theside 10 of the tongue and the face of the material M which willconstitute the top of the rafter. When the square and straight edge arein this position the line traversed by the lower edge of the side 10 ofthe tongue B and the straight edge are successively marked uponadjacentv faces of the material and this marking will indicaterespectively the cuts to be taken to give the desired vertical and roofplane angles. The reason for the correctness of the vertical out justreferred to will'be obvious while the correctness of the cut to be takento give the roof plane angle resides in the fact that the elevated endof the jack rafter meets the hip rafter at an angle of 45 degrees and asthe side 10 of the tongue B is disposed at an angle of 45 degrees to animagi- I nary level of the jack rafter being drafted the line traversedby the straight edge Z must be mathematically correct for the roof planeangle of the jack rafter.

To ascertain the roof plane angle of a hip or valley rafter having arise of eight inches per foot and a known length the square is appliedas shown in Fig. 6. In this figure the square is placed against thematerial M with the outer end of the outer side of the blade Acoinciding with the working line DD and the eight inch scale of the side11 of the tongue also coinciding with the line DD A straight edge Y isthen placed so as to lie continuously upon the side 11 of the tongue andthe face of the material M which will constitute the top of the rafter.The material is then suitably marked as described in connection with ajack rafter and this marking will indicate the correct cut to be takento give the desired roof plane angle of the hip or valley rafter. Theaccuracy of the result thus reached is dependent upon the factthat a hipor valley rafter comes in contact with other members of the roof at whatwould be if carried to an imaginary level, an angle of 45 degrees tosaid level and as the side 11 of the tongue is disposed at an angle of45 degrees to the imaginary level above referred to the cuts indicatedby the lower edge of the side 11 and the straight edge Y must ofnecessity be such as to give the desired roof plane angle.

What is claimed is:

l. A carpenters square having the inner edge of its blade scaled intoequal divisions and the outer and inner edge of its tongue scaled intodivisions equal to the divisions of the inner edge of the blade; andhaving the combined width of the tongue and the length of the bladeequal to the square root of twice the square of the length of the inneredge of the blade, said tongue and blade being scaled throughout theircombined width and length into the same number of equal divisions as theinner edge of the blade.

2. A square having the inner edge of its blade scaled into equaldivisions and its tongue constructed of a prism having the cross sectionof an isosceles triangle, the edges of said tongue being scaled intodivisions equal to the divisions of the inner edge of the blade; andhaving the combined width of the tongue and the length of the bladeequal to the square root of twice the square of the length of the inneredge of the blade, said tongue and blade being scaled throughout theircombined width and length into the same number of equal divisions as theinner edge of the blade.

In testimony whereof, I alfix my signature, in presence of twowitnesses.

FORESTER W. ROYAL.

Witnesses:

WALLACE YATES, EARL W. ANDERSON.

